IP address, known as Internet Protocol (IP) address, is your computer's or other device's unique address on the Internet.
Because, every device connected to the public Internet is assigned a unique number known as IP address.
So, basically an IP Address is a name for a device (or computer) on the Internet.

IP addresses consist of four numbers separated by periods (also called a 'dotted-quad') and look something like 109.73.111.38.
To make it easier for us humans to remember, IP addresses are normally expressed in decimal format as a "dotted decimal number"
like the one above. But computers communicate in binary form. Look at the same IP address in binary:
01101101.01001001.01101111.00100110

The four numbers in an IP address are called octets, because they each have eight positions when viewed in binary form. If you add all the positions together, you get 32, which is why IP addresses are considered 32-bit numbers. Since each of the eight positions can have two different states (1 or 0) the total number of possible combinations per octet is 28 or 256. So each octet can contain any value between 0 and 255. Combine the four octets and you get 232 or a possible 4,294,967,296 unique values!

Out of the almost 4.3 billion possible combinations, certain values are restricted from use as typical IP addresses. For example, the IP address 0.0.0.0 is reserved for the default network and the address 255.255.255.255 is used for broadcasts.

Internet Protocol (IP) technology was developed in the 1970s to support some of the first research computer networks.
Today, IP has become a worldwide standard for home and business networking as well.

Two versions of IP technology exist today. Essentially all home computer networks use IP version 4 (IPv4), but an increasing number of educational and research institutions have adopted the next generation IP version 6 (IPv6).